Prediction Of The Large Ground Deformation Induced By Seismic Liquefaction And Its Effects On Highway Engineering

In the past few years, there were lots of earthquakes happened in China. Meanwhile, our country is one of the nations that have the most serious earthquake disasters in the world. The earthquake usually threatens domestic life and property safety. Recently, many large-scale facilities have been built owing to economic developments at very fast speed in China. So the frequent earthquake is a serious latent threat to the safety of facilities construction which is in booming development. The particular history reports of earthquake disaters have illuminated that damage to pile foundations and structuces may be caused by large ground deformation (LGD) due to seismic liquefaction. This kind of damage has been observed many times in several strong earthquakes in the past. The prediction method of large ground deformation and its effect on highway engineering are researthed in this paper.(1) Based on the review of the theoretic and testing research on large ground deformation induced by seismic liquefaction, a comprehensive introduction is given to the problems of this research such as the earthquake disaster induced by large ground deformation; the methods to predict the large ground deformation and the testing on it; the character of the highway engineering during the seismic liquefaction and the different ground improvement measures against large ground deformation.(2) Then an approach to estimate liquefaction-induced ground deformations using either CPT or SPT data is recommend. And the approach is applied to predict the potential LGD which may happen on the partial region of the Su-huai highway. The outcome indicates that the proposed approach combines available results from laboratory test, capture the mechanisms of liquefaction-induced lateral spreads, and characterize the major factors influencing LGD. Furthermore this method is relatively simple and can be applied with only a few additional calculations following an SPT- or CPT-based liquefaction-potential analysis.(3) The generant process of LGD induced by seismic liquefaction is simulated by making use of Lagrangian finite difference software-FLAC3D, the effect of various parameters on the lateral spread is also analysed qualitatively.(4) The behavior and the characteristic of pile foundation for bridge that is suffering from LGD due to seismic liquefaction is analysed by using FLAC3D. The research shows that there may be excessive bending moment happened in the interfaces between lipuefied and nonliqufied soil layers. So the design of pile foundation should not just consider the dynamic effect of the superstructure. The effect of lateral spread on pile foundation can not be neglected.(5) According to the analysis of the creation mechanisms and the influence factor of the lateral spread due to seismic liquefaction, several effective engineering measures that can prevent the ground and pile foundations form earthquake disaster are propoused. Finally, some favorable suggests and prospects on the following research of this aspect are put forward.